If you type “iPhone” into the Google search bars in Firefox (left) and Safari (right), you get subtly different results. Why? After all, one is querying the same search engine.
Thanks to Pete for pointing it out.
Later: Many thanks to all who emailed pointing out that one search was on google.co.uk and the other on google.com. The great thing about the Web is that it enables one to expose one’s ignorance/carelessness so comprehensively. Headgear being eaten as you read this.